LM3478MM National Semiconductor, LM3478MM Datasheet - Page 5

• Manufacturer Part Number: LM3478MM
• Description: Pulse Width Modulation (PWM) Controller IC
• Manufacturer: National Semiconductor

Specifications of LM3478MM

• Peak Reflow Compatible (260 C): No
• Leaded Process Compatible: No
• Mounting Type: Surface Mount
• Features: High Efficiency
• Package / Case: 8-MSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Electrical Characteristics
(Continued)
Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the device
is intended to be functional. For guaranteed specifications and test conditions, see the Electrical Characteristics.
Note 2: The human body model is a 100 pF capacitor discharged through a 1.5kΩ resistor into each pin.
Note 3: All limits are guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits are 100%
tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used to calculate
Average Outgoing Quality Level (AOQL).
Note 4: Typical numbers are at 25˚C and represent the most likely norm.
Note 5: The FA/SD pin should be pulled to V
through a resistor to turn the regulator off. The voltage on the FA/SD pin must be above the maximum limit for Output
IN
= High to keep the regulator off and must be below the limit for Output = Low to keep the regulator on.
Note 6: The voltage on the drive pin, V
is equal to the input voltage when input voltage is less than 7.2V. V
is equal to 7.2V when the input voltage is greater
DR
DR
than or equal to 7.2V.
Note 7: The limits for the maximum duty cycle can not be specified since the part does not permit less than 100% maximum duty cycle operation.
Note 8: The over-voltage protection is specified with respect to the feedback voltage. This is because the over-voltage protection tracks the feedback voltage. The
overvoltage protection threshold is given by adding the feedback voltage, V
to the over-voltage protection specification.
FB
Note 9: For this test, the FA/SD pin is pulled to ground using a 40K resistor.
Note 10: For this test, the FA/SD pin is pulled to 5V using a 40K resistor.
Typical Performance Characteristics
Unless otherwise specified, V
= 12V, T
= 25˚C.
IN
J
I
vs Input Voltage (Shutdown)
I
vs Input Voltage (Non-Switching)
Q
Supply
10135534
10135503
I
vs V
(Switching)
Switching Frequency vs R
Supply
IN
FA
10135535
10135504
5
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